This invention relates to a device for controlling the movement of down hole tubulars such as drill pipe, collars, casing and production tubulars, and is particularly useful in automating the movement of down hole tubulars between the centerline of a borehole and on-site tubular storage facilities.
Moving oil field drilling and production tubulars at a well site to and fro between a storage facility for the tubulars and a precisely positioned wait station or pick-up point, or between any two wait stations or pick-up points, is an essential step in the remote control and hence the automation of the drilling and well completion processes. Such remote control and automation significantly increases safety at the drilling site and reduces the direct labor and therefore the cost of drilling and completing wells. This is especially true for deep oil and gas wells.
When a pipe handling boom or pipe arm such as that shown in U.S. Pat. Nos. 4,708,581, and 4,407,629 is used, it is important that a single tubular be positioned at the pick-up point, with no other tubulars next to either side of it, so that the pipe clamps of the pipe handling boom or other pick-up device can obtain a firm grasp on the tubular for lifting and rotating it into the drill string safely and accurately. This requirement makes it important that the individual tubulars of varying size be released by remote control.
It is an object of this invention to provide an improved feeding device which is usable with tubulars having a wide range of diameters, which is relatively simple and inexpensive to fabricate, and which is reliable in operation.